Power output in flat stages

"Daniel S. Lieb" <[email hidden]> wrote in message "]news:[email hidden]...

Quoted message said:

Catch this posted on cyclingnews.com this morning:

"To give you an idea of how much energy you save by sitting on a wheel, it takes around 50-60
percent of the power to sit behind someone compared to riding in front. In a peloton, that
effect is magnified - it's like riding in a cocoon, and even high speeds can require very little
effort. A study by a Rabobank team doctor showed the average power output of a rider during a
flat stage, where he finished in the bunch: it was only 98 Watts, which is at the very low end
of a recovery ride. "

98 Watts?! That's awfully low.

Not, apparently, if you're good at hiding from the wind...

The data were collected by Asker Jeukendrup, Ph.D., now w/ the University of Birmingham. Skeptical
sports scientists have raised the question to him as to whether the SRM was properly calibrated
(unfortunately, not all are), but he's got data on other riders showing power outputs in the low
100 W range.

Also keep in mind that when riding in a group or on rolling terrain, average power tends to
underestimate the true effort required, since the average includes all the times that power is low
or zero, e.g., when soft-pedaling to avoid running into the rider in front of you, or coasting
down a hill.

Andy Coggan

"Andy Coggan" <[email hidden]> wrote in message news:3NePa.39690

Quoted message said:

Also keep in mind that when riding in a group or on rolling terrain,

average

Quoted message said:

power tends to underestimate the true effort required, since the average includes all the times
that power is low or zero, e.g., when soft-pedaling to avoid running into the rider in front of
you, or coasting down a hill.

I should have clarified that - those zero values really impact on the average power output. e.g I've
raced at 230W / 170 bpm and trained at 230W / 130 bpm. One involves a lot of sprints/stop starts,
the other is a steady ride and I guess much more efficient.

The effects of drafting must surely be greater in a peloton than sitting behind one rider. Maybe not
hugely different, but still significant. If someone averaged 98W in a Tour stage, even a slow one,
there must be a big effect. For one person to average 36 km/h by themselves would require at least
200W (I require about 230-240W to go that speed).

cheers, Jeff

"Jeff Jones" <jeff@cyclingnews-punt-com> wrote in message
"]news:[email hidden]...

Quoted message said:

"Andy Coggan" <[email hidden]> wrote in message news:3NePa.39690

Quoted message said:

Also keep in mind that when riding in a group or on rolling terrain,

average

Quoted message said:

power tends to underestimate the true effort required, since the average includes all the times
that power is low or zero, e.g., when

soft-pedaling

Quoted message said:

Quoted message said:

to avoid running into the rider in front of you, or coasting down a

hill.

Quoted message said:

Quoted message said:

I should have clarified that - those zero values really impact on the average power output. e.g
I've raced at 230W / 170 bpm and trained at 230W

/

Quoted message said:

130 bpm. One involves a lot of sprints/stop starts, the other is a steady ride and I guess much
more efficient.

The effects of drafting must surely be greater in a peloton than sitting behind one rider. Maybe
not hugely different, but still significant.

<Snip>

That's why the peloton can catch a 5 man break so easily (Today). The more riders in the break, the
more the peloton needs to worry about them staying away.

-T